Cytokeratin 8 (CK8, K8) (original) (raw)
Stains & CD markers
Cytokeratin 8 (CK8, K8)
Last author update: 1 October 2013
Last staff update: 25 June 2021
Copyright: 2003-2025, PathologyOutlines.com, Inc.
PubMed Search: CK8[title]
Cite this page: Pernick N. Cytokeratin 8 (CK8, K8). PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/stainsck8.html. Accessed January 1st, 2025.
Definition / general
- Low molecular weight keratin (52.5-53.5 kDa)
- Usually paired with cytokeratin 18
- Component of nuclear inclusions of rhabdoid tumors (composed of tangled CK8 and vimentin) and Mallory bodies
- Mutated in malignant rhabdoid tumor (Mod Pathol 2002;15:146), chronic pancreatitis (9%, Dig Liver Dis 2003;35:416), liver disease (Proc Natl Acad Sci U S A 2003;100:6063)
- May protect hepatocytes from oxidative stress
- Cleaved by Chlamydia during infection to permit vacuole expansion necessary for replication (Infect Immun 2004;72:3863)
Positive staining - normal
- Gallbladder
- Intestine
- Liver (hepatocytes and bile ductules)
- Pancreas
- Prostate (basal cells and secretory cells)
- Simple type (single layer) epithelium including breast ducts (luminal cells)
Microscopic (histologic) images
Contributed by Leica Microsystems (Biosystems Division)
Colon (normal)
CK8 / 18 (5D3)
with intense cytoplasmic
and membranous staining
Images hosted on other servers:
Hepatocytes (residual)
are CK8+ in embryonal
sarcoma of liver
Liver disease (various)
Prostatic adenocarcinoma-top and benign prostate bottom
Squamous cell carcinoma-oral (fig C/D)